Reciprocal grate stokers



Filed Jan. 11, 1960 3 Sheets-Sheet I1 /NVE/VTOR ESL/E E GOUGH s QQ L. F.GOUGH 3,038,422

5 Sheets-Sheet 2 WA/ A AAAj/ 4.3/

`fune 12, 1962 l RECIPROCAL CRATE STOKERS Filed Jan. 11, 1960 ATTORNEYJune 12, 1962 l.. F. GOUGH 3,038,422

RECIPROCAL GRATE STOKERS Filed Jan. l1, 1960 3 Sheets-Sheet 3 FIG. 5

6** wma 155ml?.

ATTORNEY i rates My invention relates generally to improvements in solidfuel stokers for furnaces and the like, and has particular reference tograte assemblies and operating means therefor.

Briey and generally stated the present invention has for its primaryobject to improve over the reciprocal grate bar-incorporating assemblyand operating means therefor which is disclosed in my Patent No.2,695,575, dated November 30, 1954.

More specifically, the invention contemplates, in a reciprocatory gratebar-incorporating assembly, novel and highly eicient long lived meansfor supporting and simultaneously reciprocating in opposite directionsadjacent ones of one or more of a longitudinal series of fuelbedcarrying and rearwardly actuating grate bars.

Various other objects yand advantages of the invention will be referredto hereinafter or will be readily apparent to those versed in the artupon reference to the accompanying drawings forming a part of thisspecification, in connection with the detailed description thereof.

As required by the patent statute, I have illustrated in theaccompanying drawings a now preferred example of the invention, it beingunderstood that invention resides in certain novel features ofconstruction, combination and arrangement of the various parts and inmodes of operation thereof. But the illustration is to be taken asillustrative, rather than limitative, since it will be obvious toknowledgeable individuals in the furnace and allied fields that theinvention is susceptible of other mechanical eX- pressions within thespirit and scope of the subject matter claimed hereinafter.

In the drawings, wherein the same reference characters have been used todesignate the same parts wherever they appear in the several views FIG.l is a side elevational view of a stoker fired boiler embodying myinvention;

FIG. 2 is an enlarged horizontal sectional view taken on the line 2 2 ofFIG. l;

FIG. 3 is a vertical longitudinal section taken on the line 3 3 of FIG.2 and illustrating the operating means for alternate ones of alongitudinal series of grate members;

FIG. 4 is another vertical longitudinal sectional view on the line 4 4of FIG. 2, and showing the operating means for the other grate membersof the series shown in FIG. 3;

FIG. 5 is a cross-sectional view on a still larger scale and taken onthe line 5 5 of FIG. 2. Referring to the drawings by referencecharacters, and turning to FiG. l, numeral 5 indicates the boiler of astoker embodying my invention and which provides the fire box 6, base'7, grate assembly 8, fuel hopper 95. The fuel hopper 9 is supportedupon the fuel feeding chamber 10 which latter is carried lby the forwardend of a base carried grate bar-supporting plate 12 that is incorporatedin the `base 7.

Within the fuel feeding chamber 10 works the pusher 11 for supplyingfuel to the grate assembly 8 in the same fashion as is described andillustrated in my prior Patent No. 2,695,575, dated November 30, 1954.

FIGS. 3 and 4 illustrate the grate supporting plate 12 as having thedepending side and end walls 12a, 12b, respectively, which are supportedby a frame that is provided by the Stoker base '7. This base-providedframe comprehends angle-form side bars 13 and end bars 14 which supportthe depending plate Walls 12a, 12b as tnt shown. Also incorporated inframe 13, `14 is a longitudinally extending bar 13a which is carried byend bars 14.

In carrying out the invention (see FIGS. 1 and 3), I provide the stokerlbase 7 with a forward extension 15 of the base-provided frame 13, 14heretofore referred to. This forward frame extension 15 has the sidemembers 15a and the outer end cross member 15b.

The forward frame extension 15 provides the bearing member 16 in whichis pivoted, as indicated at 17, the rear end of a motor cylinder 18 orthe like within which works the reciprocatory piston 19. The outer endof piston 19 is pivoted, as at 20, to the crank arm 21 which is fast ona main rock shaft 22 that is journalled in bearings 22a supported by theside bars 13 of the frame eX- tension 15, as is clearly illustrated inFIGS. 2 and 3.

From the foregoing, it will be understood that reciprocation of thepiston 19 rocks the main rock shaft 22 back and forth. A crank 23 whichis fast on the main rock shaft 22 is pivoted as at 24 to the dependinglug 11a of the fuel pusher 11 as indicated in FIG. 3. Thus the operationof the main rock shaft 22 results in a reciprocatory movement of thepusher 11 to supply coal or other fuel to the rear top surface portionof the grate barsupporting plate 12.

It may be noted at this time that the grate bar-supporting plate 12 isprovided with two longitudinal series of aligned transversely extendingopenings 25. The respective plate openings 25 are covered by grate bars26 or 27 so that there are two laterally spaced series of the grate bars26, 27 as is clearly indicated in FIG. 2. Grate bars 26, 27 are arrangedalternately in each series and corresponding bars are in end alignment,as shown.

As is usual in the art, adjacent grate bars 26, 27 of each series arereciprocated back and forth in opposite directions and are so formed asto progressively advance the burning fuel towards the rear end of thegrate assembly 8.

A description of the operation of the grate bars 27 will now oeundertaken. Since the operating means for bars in each row is the same,a description of one will suiiice `for both. In carrying out this phaseof the invention, I provide the main rock shaft 22 with a xedlydepending crank 28, the outer end of which is pivoted as at 29 to theforward end of a link 30. The rear end of link 311 is pivoted as at 31to the upper end of a crank 32 which is fast on the rock shaft 33 thatis journalled in bearings 33a, secured =to the undersurface of the eX-tension side members 15a as indicated. The rock shaft 33 has thedepending crank 34 to which is pivoted, as at 35, the forward end of aconnected linkage .36, 36a which has the pivot connections 37 with thedepending crank arms 38 of superjacent rock shafts 39. The respectiverock shafts 39 are journalled in bearings 40 mounted on bars 13, 13a andinclude upwardly extending crank arms 41 which are spaced longitudinallyof the respective rock shafts 39. The upper ends of the crank arms 41 ofeach shaft 39 have welded, or otherwise secured thereto, the rods 42which Work in the depending slotted lugs 27a of the respective gratebars 27 of each series 26, 27, as indicated in FIG. 3. Thus it will beclear that upon operation of the piston 19 of the motor 13, the alignedgrate bars 27 which are alternate ones of each of the longitudinalseries of grate bars will be reciprocated back and forth;

Corning now to the operation of the set of aligned grate bars 26 of thetwo longitudinal grate bar series and turning to FIG. 4, it will `benoted that the main rock shaft 22 has a second depending crank arm 43pivoted as at 44 to the rear end of a linkage 45J 45a which is pivotedat longitudinally spaced points as at 46 to the lower ends of the crankarms 47. These crank arms 47 are fast on the shafts 48 which arejournalled in bearings 49 carried `by the longitudinal base providedframe members 13 and 13a. The rock shafts 43 have the upwardly extendingcranks Sil which are spaced longitudinally of the respective shafts 48and whose upper ends have made fast thereto the rods 51 which correspondto the rods 42 shown in FIG. 3 that are carried by the crank arms 41.The crank-carried rods 51 of FIG. 4 engage in the slots ofdepending lugs26 of the respective aligned grate bars 26 of each series so that whenthe main crank shaft 22 is driven, the grate bars 26 will bereciprocated back and forth on the supporting surface of the grate plate12.

From a comparison of FIGS. 3 and 4, it will be apparent that when, forinstance, the grate bars 26 of each grate bar series are being shiftedforwardly on the plate 12, the adjacent grate bars 27 of each serieswill be simultaneously actuated rearwardly and vice versa.

The grate bars 26 and 27 `are duplicates of one another and provide thethickened dual pushing rear edges, the forward edges of the grate barsbeing thin so as to admit of fuel riding up on same. Also some or all ofthe grate bars 26, 27 are provided with the inverted frusto-conicalopenings therethrough for better actuation of the tire bed, and forupdraft purposes.

Although not forming a part of the present invention, it will be notedfrom an inspection of FIGS. 2, 3 and 4 that the grate supporting plate12 provides the sinous cooling fluid flow or passage coil 52. Thispassage 52 traverses the portions of the grate plate 12 between theopenings 25 therein through which the slotted grate lugs 26a, 27aextend; and the liow of fluid therethrough from a suitable source servesto cool plate 12 and the subjacent space.

As herein shown, passage 52 has an inlet 53 connected to a low part ofboiler 5 and an outlet connected to a high part thereof. A suitable pump55 in the passage inlet 53 provides forced circulation.

The grate bar-supporting plate 12. has a number of important functionsaside from its contribution to smooth operation of grate bars 26, 27.For instance, the forward end of said plate 12 constitutes, as indicatedin FIG. 3, a support for the fuel feeding chamber 10.

Also the side and end walls 12a, 12b of said plate y1.2 in `cooperationwith the novel base 7 provided angle iron frame 13, 14 effects adesirable spacing of the plate 12 and the re bed-supporting grate bars26, 27 above the grate bar-actuating rock shafts 39, 43, theirsupporting bearings and the subjacent operating linkage 36, 36a and 45,45a. Thus heat induced deterioration of the parts mentioned ismaterially reduced.

The -base 7 provided frame 13, 14, 15 is also an important feature ofthe invention, it being understood, of course, that the forward motor 18and main rock shaft 22 are entirely supported on the frame extension 15which is functionally integral with the main plate 12 supporting portion13, 14 of said frame. Thus the novel base-carried frame 13, 14, enablesme to dispose all of the linkage 36, 36a and 45, 45a at a point verysubstantially below the fire bed to avoid heat damage thereto.

Further to be noted is the fact that the `grate-supporting plate 12,12a, 12b is removably supported by frame bars 13, 14 so as to admit ofready access to shafts 39, 48. Expended fuel, usually in the form ofclinkers is discharged -from the grate onto the usual dump plate 56.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. In a solid-fuel burning furnace, a support base including at least apair of spaced, vertically extending, parallel side walls, a pair ofhorizontally disposed, inwardly projecting, mutually parallel opposedside bars secured on intermediate portions of said side Walls, said sidebars including aligned, opposed bearing means, shaft means journaled insaid bearing means defining an axis of rotation transversely of saidside bars, a substantially planar grate-support plate including a pairof parallel side plates depending from said grate-support plate andincluding coplanar lower edges removably reecived on said side bars forsupporting said grate-support plate a substantial distance above saidside bars, said grate-support plate including a longitudinally spacedseries of aligned openings, grate bars reciprocally supported on saidgrate-support plate in operative relation to said gratesupport plateopenings, and a longitudinally disposed force-transmitting meansdisposed beneath said side bars and including vertically extending,oscilatable levers intermediately pivoted on said shaft means, saidvertically extending levers including upper terminal abutment means,said grate bars including abutment means extending through said openingsand abutingly and removably engaging said terminal abutment means onsaid vertically extending levers.

2. The structure of claim l; said grate support plate including anextension support portion exteriorly of said base forward fuel-feedingchamber supported on said extension support portion and communicatingwith the upper surface of said grate support plate, fuel-pusher means insaid fuel-feeding chamber for urging fuel onto the upper surface of saidgrate plate, power means mounted on a portion of said support base, andforce transmitting means connected to said pusher means and said forcetransmitting means for simultaneously operating said grate bars andfuel-pusher means.

3. The structure of claim l; alternate grate bars cornprising twolongitudinally spaced, separate series, said force transmitting meansincluding separate linkage members each pivotally connected to thevertically pivotal levers of the grate bars of the respective series forsimultaneously reciprocating alternate grate bars of each series ofgrate bars in opposite directions.

4. The structure of claim 3; said grate support plate including anextension support portion exteriorly of said base forward fuel-feedingchamber supported on said extension support portion and communicatingwith the upper surface of said grate support plate, fuel-pusher means insaid fuel-feeding chamber for urging fuel onto the upper surface of saidgrate plate, power means mounted on a portion of said support base, andforce transmitting means connected to said pusher means and said forcetransmitting means for simultaneously operating said grate bars andfuel-pusher means.

5. The structure of claim 1; the vertically pivotal levers beingdisposed in opposed pairs beneath opposite ends of and intermediately ofeach grate bar, said detachably engageable abutment portions of saidgrate bars and levers comprising a rod secured at opposite ends to theupper ends of said opposed pairs of levers, said grate plates eachincluding downwardly opening lugs extending into said grate plateopenings and removably and pivotally received on one of said rodsdisposed therebeneath.

References Cited in the file of this patent UNITED STATES PATENTS945,469 Mapel Jan. 4, 1910 1,440,939 Simmons Jan. 2, 1923 2,276,327Mayers Mar. 17, 1942 2,385,027 Preston Sept. 18, 1945 FOREIGN PATENTS438.560 Italy Aug. 17, 1948

